1. Field of the Invention
This invention relates to the field of methods for breaking foams and apparatus useful therefor.
II. Description of the Prior Art
The problem of breaking foams is frequently encountered when untimely foams are involved, for example foams formed during fermentation, mixing or manipulation of reactants or in dye baths or foams intentionally produced in the techniques of concentration, separation and fractionation by foaming.
Numerous solutions have been proposed to break foams but none of them have been fully satisfactory. Foam-breaking methods of the centrifugal, chemical, thermal and sonic type are known. The effectiveness of centrifugal foam-breakers is very uncertain. They are complex, consume energy and very often dessicate the foam without breaking it. Chemical foam-breakers require the addition of an anti-foaming agent which brings about the rupture of the foam. The anti-foaming agents employed, for example the silicone oils, are often expensive and present contamination problems. Thermal foam-breakers are based on the fact that a significant increase or decrease in temperature can destroy the stability of foams, however, foam-breakers of this type often require a significant input of energy and can often lead to the cracking of certain fragile molecules. The sonic foam-breakers which are employed are of the ultrasonic type. They are uneconomical and permit breaking of only a small volume of foam.